This application is related to Japanese Patent Application No. 2001-302061 filed on Sep. 28, 2001, whose priority is claimed under 35 USC xc2xa7 119, the disclosure of which is incorporated by reference in its entirety.
1. Field of the Invention
The present invention relates to a printing apparatus, more particularly a printing apparatus provided with a maintenance section for performing maintenance for a print head of inkjet type.
2. Description of Related Art
Usually, an ink-jet printer is provided with a maintenance station for executing a maintenance operation on its print head by wiping an ink discharge nozzle of the print head, discharging ink from the nozzle or sucking ink out of the nozzle before sealing (capping) the nozzle. The maintenance station is typically mounted on one end of a track on which the print head is placed. The track is provided in a direction perpendicular to a paper feed direction.
In such an ink-jet printer, the print head is moved to the maintenance station provided with a cap section, and the above-mentioned maintenance is done. The maintenance operation is performed regardless of the printing operation of the print head.
Also a cover is reclosably attached to a case of the printer for allowing user""s maintenance such as replacement of the print head and an ink tank of the print head placed on the track.
In the case where the printer executes the maintenance operation regardless of the opening or closing of the cover, the printer does not stop the maintenance operation even if a user opens the cover. Accordingly, the user is required to wait for carrying out the user""s maintenance until the printer completes the maintenance operation. Also the user may come in contact with the print head moving on the track when the user opens the cover.
Japanese Unexamined Patent Publication HEI 2(1990)-162056 discloses an ink-jet printer having a cover for covering a power supply switch, an opening/closure sensor for detecting an open/closed state of the cover, and a cap section for sealing a nozzle of a print head for preventing clogging owing to the drying of the nozzle when the print head is not in operation. During printing, the open/closed state of the cover is monitored. If the cover is opened, the printing is interrupted, the print head is moved to the cap section and the nozzle is sealed.
Japanese Unexamined Patent Publication HEI 2001-71587 discloses an ink-jet printer having a cover capable of opening an inside when an ink tank or a print head is replaced. In this printer, if the print head is located at the end of a forward way of a track when the user opens the cover, the print head moves to a maintenance section at a starting end of a track.
In the above-mentioned ink-jet printers, if they are placed in a dry environment, the nozzles become dry while the print heads move. Consequently the nozzles are liable to clog and the maintenance operation cannot be done effectively.
The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a printing apparatus offering an improved safety to users when the cover is opened and allowing a user""s effective maintenance.
The present invention provides a printing apparatus comprising a print head section having a nozzle for discharging ink; a paper feed section for feeding paper in a paper feed direction; a movement section for reciprocally moving the print head along a track formed in a direction perpendicular to the paper feed direction; a maintenance section for performing a maintenance operation on the nozzle; a case for accommodating the above-mentioned sections; a cover attached to the case in an openable and closable manner; a detection section for detecting open and closed states of the cover and outputting detection signals representative of the open and closed states of the cover; and a control section for controlling drive of the movement section and the maintenance section according to the detection signals output by the detection section, wherein the maintenance section includes two maintenance stations mounted on both ends of the track, and the control section gives an instruction such that the print head moving to one of the maintenance stations is stopped at a stop position established on the track, in response to the detection signal representative of the open state of the cover.
That is, if a user opens the cover while the maintenance operation is being carried out on the print head, the print head moving toward one of the maintenance stations for the next maintenance step is stopped at the stop position established on the track. Accordingly, the print head does not traverse in front of the user, and the user can immediately carry out user""s maintenance such as replacement of an ink tank and the print head on the stopped print head.
The control section, in response to the detection signal representative of the open state of the cover, may give an instruction such that the print head moving along the track is moved to one of the maintenance stations which is closer to the print head. With this construction, the user can immediately carry out user""s maintenance such as replacement of the ink tank and the print head on the print head moved to the maintenance station. Also a nozzle of the print head can be inhibited from drying during a period when the maintenance operation is interrupted by the user""s maintenance.
Further, after the print head is moved to the maintenance station, the control section may give an instruction such that the print head is moved again along the track and is stopped at the stop position. With this construction, the user can immediately carry out user""s maintenance such as replacement of the ink tank and the print head on the stopped print head.
After the print head is stopped at the stop position, the control section may give an instruction such that the maintenance operation is resumed, in response to the detection signal representative of the closed state of the cover. With this construction, the user can carry out the user""s maintenance safely, and also the maintenance operation initiated by the control section can be performed without delay.
According to a step of the maintenance operation at the time of detecting the open state of the cover, the control section may determine from which step the maintenance operation should be resumed, from a step next to said step or from the first step of the maintenance operation. With this construction, it is possible to avoid the interruption by the stopping of the print head of a step of the maintenance operation which is desirably performed continuously. Also, in the case where a step of the maintenance operation which need not be performed continuously is being performed at the time of detecting the open state of the cover, the step is interrupted and the user can immediately carry out the user""s maintenance on the print head at the stop position.
For resuming the maintenance operation from the next step, the control section may select one of the two maintenance stations according to the step of the maintenance operation at the time of detecting the open state of the cover, and give an instruction such that the print head is moved to the selected one of the maintenance stations and the maintenance operation is resumed.
More particularly, in the case where the step of the maintenance operation at the time of detecting the open state of the cover is not affected by interruption, the maintenance operation is resumed from the next step. Such a step that is not affected by interruption is a step where the print head starts to move to a predetermine maintenance station for the first step of the maintenance operation, a step where a spitting step of causing the nozzle to discharge the ink for merely moistening the nozzle is finished, or the like.
On the other hand, in the case where the step of the maintenance operation at the time of detecting the open state of the cover is desirably performed continuously, for example, in the case of a capping step of wiping the nozzle, discharging the ink from the nozzle for moistening the nozzle and the cap and then capping the nozzle, the maintenance process is resumed from the first step of the maintenance operation for preventing the nozzle and a cap from becoming dry due to the interruption of the maintenance process.
Therefore, when the cover is closed, the maintenance operation can be resumed in an optimal way according to the step of the maintenance operation at the time of detecting the open state.
The step of the maintenance operation at the time of detecting the open state of the cover may be recognized according to a time having elapsed from the beginning of the maintenance operation. This constitution eliminates the need of a sensor such as an encoder verifying the position of the print head for performing the maintenance operation after the cover is closed, and thus simplifies the structure of the printing apparatus.
After a predetermined time elapses from the time of detecting the open state of the cover, the control section may give an instruction such that the print head stopped at the stop position is moved to one of the maintenance stations. This constitution prevents the nozzle and the cap from drying owing to a long interruption.
The present invention may provide a printing apparatus having maintenance stations provided with at least one of a wiper section for wiping the nozzle, an ink discharge section for causing the nozzle to discharge a predetermined amount of ink, a waste ink receiving section for receiving the discharged ink, a cap section for capping the nozzle and an ink suction section for sucking the ink from the nozzle, wherein the maintenance operation comprises at least one of the steps of wiping the nozzle, causing the nozzle to discharge the ink, sucking the ink from the nozzle and capping the nozzle.
In the printing apparatus provided with the above-described maintenance stations, since both the maintenance stations on the right and left sides are provided with the ink discharge sections, the spitting action of discharging the ink from the nozzles can be performed by the maintenance sections on both the sides. Therefore, when the open state is detected, the print head can immediately proceed to the spitting acting without crossing the stop position.
Also since both the maintenance stations on the right and left sides are provided with the wiper sections for wiping the nozzles, the wiping action of wiping the nozzle can be performed by the maintenance stations on both the sides. Therefore, when the open state is detected, the print head can immediately proceed to the wiping acting without crossing the stop position.
These and other objects of the present application will become more readily apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.